Spondylarthrosis
Spondylarthrosis is a non-inflammatory degenerative condition that affects the vertebral bones of the spine, characterized by the presence of bony spurs or “osteophytes” along the edges of the bones. A bony spur may develop in a single spot or in multiple different locations along the spine. Spondylarthrosis develop along the thoracic vertebrae (chest), in the lumbar spine (lower back) and in the lumbosacral spine. In some cases, the bony spurs may become large enough that they appear to form a complete bridge between adjacent vertebral bones, which is commonly referred to as “Spondylosis Deformans”.
Etiology
In a normal spine, the vertebral bones are united by ligaments that form a flexible protection to the spinal cord. Between each vertebral bone there is an intervertebral disc that act as shock absorbers and cushions.
Research suggests a correlation between Spondylarthrosis to a degenerative disease of the intervertebral discs. In case the intervertebral discs are damaged or degenerate over time, the joints around them become less stable, resulting in abnormal motion and instability.
The formation and growth of new bone seems to be triggered by this instability and osteophytes develop to re-establish the stability of the weakened joint or joints.
Additional etiology factors are aging, injury (repetitive microtrauma due to repeated exercise or major trauma/injury) or a genetic predisposition to produce bone spurs.
Even though this condition is more common in large-breed dogs, it is a chronic condition associated with aging. Therefore, any middle-aged to older dog can be affected. Some of the overrepresented breeds are Boxers, German shepherds, and flat-coated retrievers.
Clinical signs
Most dogs with Spondylarthrosis appear to be pain-free and there will show no signs.
Clinical signs include stiff gait, lameness, pain response during spine palpation, restricted motion or other neuromuscular symptoms associated with damaged spinal cord. Signs depend on the location and severity of the deformity in the spine.
Diagnosis
Diagnosis includes physical examination, orthopedic and neurologic evaluation, blood work and diagnostic imaging.
The radiographs will reveal the presence of osteophytes along the vertebrae. Intervertebral discs and other soft tissues around the vertebrae do not show up on X-rays. Therefore, in case of clinical signs suggestive of nerve damage, advanced imaging is required such as CT scan, myelography and MRI. In these cases, the patient will be referred to a neurology specialist.
In some cases, it may be an incidental finding that is noticed when radiographs are taken for some other reason.
Treatment
Treatment depends on clinical signs of the patient and is mainly conservative. Conservative treatment includes weight reduction, controlled exercise, physiotherapy, and pain management primarily with NSAID’s. In case of nerve damage due to spinal cord compression by osteophytes, surgery might be indicated.
Prognosis
In case of an asymptomatic patient, the disease may go undetected for years. Most dogs live with an acceptable quality of life despite of limited flexibility and reduced range of motion.
Prognosis should be discussed with the owner based on imaging and patient’s response to treatment.
Sources:
Kranenburg H.C., Voorhout G., Grinwis G.C.M., Hazewinkel H.A.W., Meij B.P. Diffuse idiopathic skeletal hyperostosis (DISH) and spondylosis deformans in purebred dogs: A retrospective radiographic study. Vet. J. 2011;190:e85–e90.
Morgan J.P., Ljunggren G., Read R. Spondylosis deformans (vertebral osteophytosis) in the dog. A radiographic study from England, Sweden and U.S.A. J. Small Anim. Pract. 1967;8:57–66.
Langeland M., Lingaas F. Spondylosis deformans in the boxer: Estimates of heritability. J. Small Anim. Pract. 1995;36:166–169. doi: 10.1111/j.1748-5827.1995.tb02872.x.
